Information
-
Patent Grant
-
6786302
-
Patent Number
6,786,302
-
Date Filed
Wednesday, February 20, 200223 years ago
-
Date Issued
Tuesday, September 7, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Thorpe North & Western, LLP
-
CPC
-
US Classifications
Field of Search
US
- 403 385
- 403 386
- 403 187
- 403 396
- 403 188
- 403 169
- 403 353
- 403 170
- 403 49
- 403 246
- 403 175
- 403 176
- 403 394
- 403 4281
- 182 1786
- 182 1781
- 182 119
- 182 1868
- 182 1867
- 182 1869
- 182 1791
- 182 1785
- 052 637
- 052 6511
- 052 6551
- 052 6569
- 052 638
- 248 2184
- 248 22922
- 248 22923
- 248 3165
- 248 3166
-
International Classifications
-
Abstract
A coupling apparatus is comprised of three couplers for interconnecting three scaffolding members. The locking devices for the couplers may be of a bolt-and-nut configuration or, advantageously, of a wedge and arm, tapered circular wedge and arm or over-centre hand-lever.
Description
FIELD OF THE INVENTION
This invention relates to couplers and more particularly to couplers for interconnecting scaffolding.
BACKGROUND OF THE INVENTION
Scaffolding is commonly constructed from lengths of steel or aluminum tubes interconnected to each other to form an open structural framework. The size and configuration of the structure depends on the application. The interconnection of the tubes is normally made by two right angle couplers (“double couplers”) which are joined together. One of these double couplers can interconnect two of the three tubes that will normally meet at a right angle crossing of a scaffold structure. A second double coupler is required to interconnect a third tube to the first two.
The couplers are normally locked to the tubes by one or more nut and bolt locking devices. However, such couplers suffer from disadvantages. Their fastening and unfastening is time consuming and is inconvenient in requiring use of a wrench. Additionally, two hands are normally required to hold the coupler during the initial stages of fastening and the nuts and bolts are often corroded, making it difficult to thread and tighten the nuts. Also, the locking device may be under or over tightened on the tubes, leading to slipping or thread stripping respectively, which may compromise the safety of the scaffold structure.
SUMMARY OF THE INVENTION
The invention may be summarised according to a first broad aspect as a coupling apparatus for interconnecting three scaffold members comprising: a support coupler and two connector couplers for attachment to three scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three scaffold members at relative angles to each other.
The invention may be summarised according to a second broad aspect as a two coupler apparatus for interconnecting two scaffolding members wherein at least one coupler is defined by: a base interconnected to a second coupler; a lever hinged to the base, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; an arm hinged to the base; the lever having an slot sized to receive the arm; the arm defining a hole positioned to extend beyond the lever when the arm is within the slot; a wedge adapted for insertion through the hole to slidably move against the lever when the arm extends within the slot to wedge the arm within the lever whereby the scaffold member is locked within the at least one coupler.
The invention may be summarised according to another broad aspect as a two coupler apparatus for interconnecting two scaffolding members wherein at least one coupler is defined by: a base interconnected to a second coupler; a lever hinged to the base, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; an arm hinged to the base, the arm having a protrusion at a free end; the lever having an slot adapted to receive the arm; a circular wedge pivotally mounted on the arm, the circular wedge circumferentially increasing in thickness to define a cam surface for engagement with the protrusion; the circular wedge being rotatable on the arm between the lever and the protrusion in a direction of increasing thickness to create a wedging action between the protrusion and the cam surface acting to press the lever onto the scaffold member to lock the scaffold member within the pocket.
The invention may be summarised according to a further broad aspect as a two coupler apparatus for interconnecting two scaffolding members wherein at least one coupler is defined by: a base interconnected to a second coupler; a lever hinged to the base, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; an over-centre hand-lever mechanism for intercoupling the base and the lever, the over-centre hand-lever mechanism having an adjustable length and being selectively actuatable when intercoupling the base and the lever to lock the lever and the base to a scaffold member.
Advantageously, the triple coupler allows three scaffold members to be interconnected with only one coupling apparatus thereby replacing the two double couplers normally used. Assembly is then achieved by the handling of one apparatus instead of two.
Additionally, the angle between the three scaffold members can be fixed by the triple coupler. This eliminates the need to adjust the angle of a second double coupler relative to a first double coupler as is necessary where two double couplers are used.
Specific embodiments of the couplers, namely the wedge coupler, the circular wedge coupler and the hand-lever coupler, have the advantage that they do not rely on threaded bolts and nuts to fasten the couplers around the scaffold members. This eliminates the problems of stripped or rusted threads associated with bolt-and-nut locking devices.
Additionally, the hand-lever coupler may be fastened or unfastened quickly without the use of any hand tools.
Also, the wedge coupler and the circular wedge coupler are simple to fabricate, may be fastened or unfastened rapidly and the circular wedge coupler has no separable parts.
Other aspects and features of the invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described with reference to the attached drawings in which:
FIG. 1
is a perspective view of a bolt-and-nut triple coupler in which segments of scaffolding tubes are shown.
FIG. 2
is a perspective view of the bolt-and-nut triple coupler of FIG.
1
.
FIG. 3
is a perspective view of a wedge triple coupler.
FIG. 4
is an enlarged perspective view of a wedge and an arm used in the triple coupler of FIG.
3
.
FIG. 5
is a perspective view of a circular wedge triple coupler.
FIG.
6
A and
FIG. 6B
are perspective views of a circular wedge and arm, shown separately and assembled, respectively, of the triple coupler of FIG.
5
.
FIG. 7
is a perspective view of a hand-lever triple coupler.
FIGS. 8A
,
8
B,
8
C and
8
D are perspective views of a base, an inner lever, a hand lever and a T-shaped catch assembly of the coupler of FIG.
7
.
FIG. 9
is a side view of a coupler of the hand-lever triple coupler of
FIG. 7
, with a scaffold member, in an open position.
FIG. 10
is the coupler of
FIG. 9
, shown to a larger scale, in an almost closed position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1
depicts a triple coupler
10
interconnecting a vertical scaffold member
8
A and two horizontal scaffold members
8
B,
8
C. The triple coupler
10
includes a heavy duty vertical support coupler
12
and two horizontal connector couplers
14
A,
14
B.
FIG. 2
depicts a base
16
of the vertical support coupler
12
. The base
16
has two plates
17
,
19
joined at a right angle. Two flanges
15
extend at right angles from the edges of the plates
17
,
19
. The flanges
15
have inner edges that define an arcuate pocket
22
. The flanges
15
have pair of registering holes that define a pivot axis
21
adjacent an outer end of the plate
19
and a pivot axis
28
adjacent an outer end of the plate
17
.
The base
16
further includes a lever
18
defined by a plate
25
that has two flanges
27
, and a horizontal slot
30
opening from the free end. The two flanges
27
extend from the free end of the plate
25
along its side edges and have inner edges that are arcuate. The lever
18
is pivotally connected, on the axis
21
, to the flanges
15
on the base
16
.
The coupler
12
includes a locking device
24
comprising a bolt
26
, which is pivotally connected to the base
16
on the axis
28
at the opposite side of the pocket
22
. A nut
34
is threaded on the bolt
26
which also carries a washer
32
. The horizontal slot
30
receives the bolt
26
when the bolt
26
is rotated about the pivot axis
28
and into position shown in FIG.
1
.
The vertical support coupler
12
is locked to the vertical scaffold member
8
A by the locking device
24
. The operation of the locking device
24
is as follows. The vertical scaffold member
8
A (
FIG. 1
) is placed into the pocket
22
. The lever
18
is then swung to close the flanges
27
around scaffold member
8
A. The lever
18
thus closes the pocket
22
. The flanges
27
and the flanges
15
grip the vertical scaffold member
8
A (
FIG. 1
) when the vertical support coupler
12
is closed. The bolt
26
is then swung into the slot
30
in the lever
18
and the nut
34
rotated against the washer
32
to press the lever
18
into gripping engagement with the scaffold member
8
A. Thus, when the nut
34
is tightened, the vertical scaffold member
8
A is securely locked in the pocket
22
of the coupler
12
.
The structure of each horizontal connector coupler
14
A,
14
B depicted in
FIGS. 1 and 2
is basically the same as that of the vertical support coupler
12
. Only the structure which differs will be described with reference to the lower horizontal connector coupler
14
B. Unless otherwise specified, the structure of the upper horizontal connector coupler
14
A is the same as that of the lower horizontal connector coupler
14
B.
The lower horizontal connector coupler
14
B has a stopper plate
48
near the pivot of a bolt
50
. The stopper plate
48
prevents the bolt
50
from rotating too far from its locked position when it is released. The stopper plate
48
maintains the bolt
50
at an angle in the range of 10° to 15° from the plane of a horizontal plate
43
of a base
42
.
The horizontal connector couplers
14
A,
14
B are rigidly fixed to the vertical support coupler
12
by rivets
36
. As shown in
FIGS. 1 and 2
, the horizontal connector couplers
14
A,
14
B are offset and orthogonal to each other and to the vertical support coupler
12
. The vertical plate
45
B of the base
42
of the lower horizontal connector coupler
14
B is riveted to the plate
17
of the vertical support coupler
16
and the vertical plate
45
A of the upper horizontal connector coupler
14
A is riveted to the plate
19
of the coupler
12
as is clearly shown in FIG.
2
. The vertical plate
45
B of the lower horizontal connector coupler
14
B extends below the plate
17
of the coupler
12
and the vertical plate
45
A of the upper horizontal connector coupler
14
A extends above the plate
19
of the coupler
12
. On a portion of the vertical plate
45
B, which extends below the coupler
12
, there is a reinforcing knot
40
. The reinforcing knot
40
is a roughly semi-hollow-ball shaped protrusion formed in the vertical plate
45
B. The reinforcing knot
40
prevents the bending of the vertical plate
45
B by pressing against the vertical scaffold member
8
A when a vertical force of the horizontal scaffold member
8
C against the base
42
would otherwise tend to bend the portion of the vertical plate
45
B extending below the base
16
. A vertical plate
45
A of the upper horizontal connector coupler
14
A does not have a similar reinforcing knot.
Other locking devices may be utilized as exemplified in the following Figures.
FIG. 3
depicts a triple coupler
60
which utilizes a bolt-and-nut locking device
62
to secure a vertical support coupler
64
as in
FIGS. 1
,
2
. However, two horizontal connector couplers
66
utilize a different locking device.
The couplers
66
have a base
72
with flanges having arcuate inner edges which define a pocket
76
. A lever
74
is hinged at one end to the base
72
. The lever
74
also has flanges with arcuate inner edges. The lever
74
has an outwardly open slot
78
as in the levers of the bolt-and-nut couplers of
FIGS. 1
,
2
. However, in the present embodiment, the bolt-and-nut have been replaced by an arm
70
and a wedge
68
.
FIG. 4
depicts the wedge
68
separately from the arm
70
. The arm
70
has a circular hole
71
adjacent one end and an elongate hole
80
adjacent the other end. The arm
70
is hinged to the base
72
by a pin (not shown) passing opposite the lever
74
through the hole
71
. The wedge
68
has a wide end
84
with a stopper
87
, and tapers to a narrow end
82
, which has a hole
86
defined therein.
In use, a scaffold member (not shown) is positioned into the pocket
76
and the lever
74
is rotated to close the pocket
76
around the scaffold member. The arm
70
is then rotated into the slot
78
such that a portion of hole
80
extends above the lever
74
. The small end
82
of the wedge
68
is slid through that portion of the hole
80
. As the wedge
68
(driven by hammer blows) is advanced through the hole
80
, the increasing taper of wedge
68
forces more of the arm above the lever
74
. The lever
74
is thus pressed against the scaffold member within the pocket
76
, thereby locking the scaffold member within the coupler
66
.
The wedge
68
is also designed to be retained within the hole
80
even when it is not locked against the lever
74
. In particular, the stopper
87
at the wide end
84
of the wedge
68
is sufficiently wide that it cannot fit through the hole
80
in the arm
70
. A retaining means (not shown) such as a cotter pin, rivet, or other fastener, is inserted through the hole
86
in order to retain the wedge
68
within the hole
80
.
FIG. 5
depicts a triple coupler
90
comprised of a bolt-and-nut coupler
92
and two circular wedge couplers
94
. The bolt-and-nut coupler
92
is essentially as described with respect to
FIGS. 1 and 2
but the two couplers
94
utilize another locking device. Each coupler
94
has a base
98
, with flanges having arcuate inner edges, which defines a pocket
100
. A lever
96
is hinged at one end to the base
98
. The lever
96
also has flanges with arcuate inner edges and can be swung to close the pocket
100
around a horizontal scaffold member (not shown). The lever
96
has an outwardly open slot
104
. This structure is the same as that of the bolt-and-couplers of
FIGS. 1
,
2
. However, in the present embodiment, the bolt-and-nut have been replaced with an arm
102
and a circular wedge
105
.
FIG. 6A
depicts the arm
102
and the circular wedge
105
separately. The arm
102
has a hole
101
adjacent one end for pivotal attachment to base
98
and at its opposite end a protrusion
112
projecting perpendicular to an axis of the hole
101
. The arm
102
is hinged to the base
98
, opposite the lever
96
, through the hole
101
. The circular wedge
105
has a hexagonal outer surface and a circular inner surface. The circular wedge
105
has a depression
108
, which defines the minimum thickness of the circular wedge
105
. A tapered upper surface
110
which begins at a leading edge
117
of the depression
108
and extends around the circumference of the circular wedge
105
to a stopper
114
that divides the tapered upper surface
110
from a second edge
113
of the depression
108
. When the circular wedge
105
is assembled onto the arm
102
(
FIG. 6B
) it can rotate freely about the shaft
111
of the arm
102
except when moved into engagement with the protrusion
112
. The depression
108
is sufficiently wide to receive the protrusion
112
. When the arm
102
is assembled to the coupler
96
, a spring washer
106
(
FIG. 5
) is preferably positioned on the arm beneath the circular wedge
105
.
The operation of the coupler
94
is as follows. A scaffold member (not shown) is placed within the pocket
100
. The lever
96
is swung over the scaffold member and the arm
102
is rotated into the slot
104
in the lever
96
. The circular wedge
105
rests against spring washer
106
, which rests on the lever
96
. The depression
108
rests against the protrusion
112
. To tighten the locking device, the circular wedge
105
is pressed against the lever
96
and rotated to position the protrusion
112
against a leading edge
117
of the tapered upper surface
110
. As the circular wedge
105
is further rotated (e.g. by use of a wrench), the wedge action of the surface
110
against the protrusion
112
presses the lever
96
against the scaffold member within the pocket
100
, thereby locking the scaffold member to the coupler
96
. The stopper
114
limits the rotation of the circular wedge
105
against the protrusion
112
thereby preventing the circular wedge
105
from being over-rotated. The spring washer
106
secures the circular wedge
105
against slipping once it is tightened.
A triple coupler
120
of
FIGS. 7
to
10
include a bolt-and-nut vertical support coupler
122
, as in
FIGS. 1
,
2
and two horizontal couplers
124
. As best depicted in
FIG. 8A
, each coupler
124
has a base
126
with a rear vertical plate
214
and a bottom plate
213
joined at a right angle to a bottom edge of the rear vertical plate
214
. A latch plate
209
is joined to the top edge of the rear vertical plate
214
and extends outwardly and slightly downwardly. A square hole
210
extends through the latch plate
209
. Two flanges
211
extend along opposite edges of the plates
213
,
214
. The inner edges of the flanges
211
define a arcuate pocket
144
(FIG.
7
). The flanges
211
have aligned holes
212
adjacent the outward end of the plate
213
.
An inner lever
128
is hinged to the holes
212
of the base
126
. The inner lever
128
, as shown in
FIG. 8B
, has a curved plate
215
with a slot
218
defined at its lower edge. The curved plate
215
has two upper ears
216
at its upper corners and two lower ears
241
at its lower corners. Aligned holes
217
extend through each of the ears
241
and aligned holes
240
extend through each of the ears
216
. A hinge pin
136
(
FIGS. 9
,
10
), extending through holes
212
and
217
, pivotally connects inner lever
128
to the base
126
.
A hand lever
130
shown in
FIG. 8C
is also pivotally connected to the inner lever
128
. The hand lever
130
has a main plate
219
with a curved handle
221
extending downward from its lower edge. A narrow elongate vertical hole
225
is cut through the centre of the main plate
219
. A wide upwardly open slot
224
extends downward from the upper edge of the main plate
219
. Two side plates
220
are joined at right angles to upper side edges of the main plate
219
. Two aligned holes
223
are defined in the outermost ends of the side plates
220
and two aligned holes
222
are defined in the side plates
220
at a intermediate location. The specified hinge pin,
150
(
FIGS. 9
,
10
) extend through pairs of holes
223
and
240
to pivotally connect hand lever
130
to the inner lever
128
as best seen in FIG.
9
.
A T-shaped catch assembly
164
of
FIG. 8D
is comprised of a pin member
226
and a hook member
227
. The pin member
226
has a circular protrusion
229
extending from each end. The protrusions
229
are slightly smaller in diameter than the holes
222
in the hand lever
130
. The pin member
226
also has a square hole
228
extending through it. The hook member
227
has a plate
231
with a hook
230
at one end. Extending from an opposite end of the plate
231
is a tapered neck
232
, which joins to a rectangular section
233
that is slightly smaller in size than the hole
228
in the pin member
226
. The rectangular section
233
is joined to a bolt section
234
threaded for engagement by a nut
236
.
To assemble the hook member
227
to the pin member
226
, the bolt section
234
and the rectangular section
233
of the hook member are inserted through the hole
228
in the pin member
226
. The nut
236
is then threaded onto the bolt section
234
to retain the pin member on the hook member. The T-shaped catch assembly
164
is then connected to the hand lever
130
by outwardly flexing the side plates
220
and inserting projections
229
of the pin member
226
into the holes
222
of the hand lever
130
.
A security device
134
,
FIGS. 9
,
10
, has a catch
137
slidably positioned at an outer face of the hand lever
130
. An L-shaped hook member
138
having a hook
139
and a plate
141
joined at a right angle is slidably positioned at the inner face of the hand lever
130
. The catch
137
and the plate
141
of the L-shaped hook member
138
are interconnected and held in position by a screw
143
extending through the hole
225
in the hand lever
130
. A spring
140
is located in the hole
225
between an extension
142
of the L-shaped hook member
138
protruding through the hole
225
and one end of the hole
225
. The spring
140
is retained in the hole
225
by the plate
141
and the catch
137
, which block opposite sides of the hole
225
. The catch
137
and the L-shaped hook member
138
are biased away from the handle
221
by the spring
140
.
The operation of the coupler
124
is described with regard to
FIGS. 9 and 10
. A scaffold member
160
is placed in the pocket
144
. The hand lever
130
is used to rotate the inner lever
128
to close the pocket
144
. At the same time, the T-shaped assembly
164
is rotated until the hook
230
is inserted into the hole
210
of the base
126
and hooked around the plate
209
. The hand-lever
130
is then counter rotated until the hook
139
catches around the hinge pin
136
. The spring
140
biases the hook
139
around a central part of the hinge pin
136
to secure the coupler
124
.
The over-centre design on the hand lever
130
also helps to hold the coupler
124
closed. The hook member
227
pivots around the protrusions
229
. When closed, the axis of protrusions
229
lies below a plane defined by the hinge pin
136
and the edge of the hole
210
. In this configuration, the outward force of the scaffold member
160
operating along that plane tends to further rotate the hook member
227
around the axis of the protrusions
229
to force the protrusions
229
downward rather than opening the coupler.
The functional length of the hook member
227
may be adjusted by rotation of the nut
236
to vary the force required to release the hand lever. A set of double convex washers (not shown) are placed over the bolt end
234
before threading the nut
236
onto the bolt end
234
in order to provide the resistance necessary to accommodate the over centre locking action of the hook
230
.
To release coupler
124
, the catch
137
is depressed towards the handle
221
to press the extension
142
against the spring
140
. The compression of the spring
140
allows the L-shaped hook member
138
to clear the hinge pin
136
when the hand lever
130
is rotated so that the protrusions
229
are above the plane of the hinge pins
136
and the edge of the hole
210
.
The gripping action of the hand lever coupler
124
coupler may not be as secure as other couplers described herein but has the advantage of rapid action.
It will be understood that the grip of the couplers herein described can be improved by designing some indentations on portions of the couplers which contact the scaffolding members. For example, the grip of the coupler described with reference to
FIGS. 7
to
10
can be improved by designing some indentations on the curve plate
215
which contacts the scaffold tube.
Both the coupler and the scaffold members described herein are typically comprised of steel or aluminum but may be made of any suitable material. Additionally, the scaffold members are shown to be tubular but may be of other cross-sectional shapes including rectangular members.
Alternative arrangements of the triple coupler are contemplated including interconnecting the couplers at other angles or pivotally interconnecting them. Additionally, other means of interconnecting the couplers may be used such as welding or casting as a unitary assembly.
Although the couplers may be used in different orientations, it is preferable to utilize a bolt-and-nut coupler for the vertical scaffold member because it achieves a firmer grip and is less prone to unintended loosing.
It will also be understood that the couplers described with respect to
FIGS. 3
to
9
may be used for coupling devices other than triple couplers. In particular, they may be used for an orthogonal, a parallel or a rotatable two coupler apparatus.
The above description of embodiments should not be interpreted in any limiting manner since variations and refinements can be made without departing from the spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents.
Claims
- 1. A coupling apparatus for interconnecting three scaffold members comprising:a support coupler and two connector couplers for attachment to three respective scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the two connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three respective scaffold members at relative angles to each other; wherein the pocket of at least one of the two connector couplers is defined by a base interconnected to the support coupler and a lever hinged to the base, the base and the lever defining the pocket for laterally receiving a length of a scaffold member; and wherein the locking device of the at least one of the two connector couplers comprises: an arm hinged to the base of the at least one of the two connector couplers; the lever having an slot adapted to receive the arm; the arm defining a hole positioned to extend beyond the lever when the arm is within the slot; a wedge adapted for insertion through the hole to slidably move against the lever when the arm extends within the slot to wedge the arm within the lever whereby the scaffold member is locked within the at least one of the two connector couplers.
- 2. The coupling apparatus of claim 1 wherein the wedge further comprises:a wide end which is wider than the hole is long; and an hole defined in a narrow end of the wedge adapted receive a blocker to prevent the narrow end of the wedge from passing through the hole.
- 3. The coupling apparatus of claim 1 wherein the base, of the at least one of the two connector couplers, further comprises a means of limiting the rotation of the arm from a vertical extension when the arm is not engaged with the lever.
- 4. The coupling apparatus of claim 3 wherein the means of limiting the rotation of the arm comprises a stopper plate extending from the base, of the at least one of the two connector couplers, outside the pocket adjacent the hinge.
- 5. A coupling apparatus for interconnecting three scaffold members comprising:a support coupler and two connector couplers for attachment to three respective scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the two connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three respective scaffold members at relative angles to each other; wherein the pocket of at least one of the two connector couplers is defined by a base interconnected to the support coupler and a lever hinged to the base, the base and the lever defining the pocket for laterally receiving a length of a scaffold member; and wherein the locking device of the at least one of the two connector couplers comprises: an arm hinged to the base of the at least one of the two connector couplers, the arm having a protrusion at a free end; the lever having an slot sized to receive the arm; a circular wedge pivotally mounted on the arm, the circular wedge circumferentially increasing in thickness to define a cam surface for engagement with the protrusion; the circular wedge being rotatable on the arm between the lever and the protrusion in a direction of increasing thickness to create a wedging action between the protrusion and the cam surface acting to press the lever onto the scaffold member to lock the scaffold member within the pocket.
- 6. The coupling apparatus of claim 5 wherein the circular wedge further comprises a stopper at a widest thickness of the circular wedge adapted to prevent the circular wedge from rotating beyond the stopper.
- 7. A coupling apparatus for interconnecting three scaffold members conspiring:a support coupler and two connector couplers for attachment to three respective scaffold members; the support coupler having a base interconnected to the connector couplers, a lever hinged to the base, and a locking device, the base and the lever defining a pocket for laterally receiving a length of a scaffold member; the two connector couplers each defining a pocket for receiving a length of a scaffold member and having a locking device; each of the locking devices being movable from a release condition, to allow a scaffold member to be positioned in or removed from the pocket, to a locked position, to secure the scaffold member in the coupler; wherein the pockets are oriented to secure three respective scaffold members at relative angles to each other; wherein the pocket of at least one of the two connector couplers is defined by a base interconnected to the support coupler and a lever hinged to the base, the base and the lever defining the pocket for laterally receiving a length of a scaffold member; and wherein the locking device of the at least one of the two connector couplers comprises: an over-centre hand-lever mechanism for intercoupling the base and the lever of the at least one of the two connector couplers, the over-centre hand-lever mechanism having an adjustable length and being selectively actuatable when intercoupling the base and the lever to lock the lever and the base to a scaffold member.
- 8. The coupling apparatus of claim 7 wherein the over-centre hand lever mechanism includes:a hand lever that is hinged to the lever of the at least one of the two connector couplers; and an adjustable length hook member that is hinged to the hand lever; wherein the adjustable length hook member is selectively engagable with the base of the at least one of the two connector couplers and the over-centre hand lever mechanism is selectively actuatable to lock the lever and the base to a scaffold member by turning the hand lever about its hinge with the lever while the adjustable length hook member is engaged with the base.
- 9. The coupling apparatus of claim 8 further comprising a latching device which operates, when the locking device is locked, to clamp the hand lever to the lever, the clamping device comprising:a second hook member attached to the hand lever and biased to latch the hand lever in locked position.
US Referenced Citations (17)
Foreign Referenced Citations (7)
Number |
Date |
Country |
878880 |
Jun 1953 |
DE |
1684361 |
Oct 1970 |
DE |
2753067 |
May 1979 |
DE |
2234804 |
Jan 1975 |
FR |
2081797 |
Feb 1982 |
GB |
11172912 |
Jun 1999 |
JP |
WO8806222 |
Aug 1988 |
WO |